Mo. Rev. Stat. § 473.139

Upon petition of an executor or administrator, and after the filing of his final settlement as required by subdivision (3) of subsection 2 of section 473.540, the court, for good cause shown, may permit him to resign and upon accepting his resignation shall revoke his letters. The effect of the resignation and revocation is the same as in other cases of revocation of letters. The petition may be heard without notice or after giving notice to the persons and in the manner directed by the court.